The major goal of the imaging core is to facilitate the use of quantitative and qualitative imaging techniques in the analysis of transport physiology at the cellular level. New technologies are now available for greater resolution of localization of specific target proteins as well as permitting vital microscopy where dynamic changes can be identified. Paraffin section light microscopy has been expanded to include immunolocalization of specific proteins as well as the utilization of in situ hybridization and in situ reverse transcription for localization of specific mRNAs. The capability and resolution of immunofluorescence microscopy has been advanced by the introduction of confocal microscopy. In addition, confocal microscopy can be applied to vital tissues, and analyses of changes in intracellular ion concentration can be assessed at the tissue level using ion sensitive fluorochromes. Video imaging and analysis of intracellular ion concentrations using fluorochromes is now well established, and gives accurate quantitative information by using dual excitation/emission ratio analysis. The utilization of electron microscopic immunocytochemical techniques has also been improved for greater accuracy in localization using immunogold and in situ hybridization techniques. The value of all of these techniques has also been enhanced by the availability of computer driven image analysis systems. The imaging core will provide expertise and assistance in the utilization of light, immunofluorescence, confocal, atomic force and electron microscopy with particular emphasis on immunocytochemistry, vital microscopy and image analysis. The facility will give access to these specialized techniques and the equipment necessary to apply them and will form a focal point for collaboration between members of the program project.